Process of making clad-metal articles.



J. F. MONNOT. PROCESS OF MAKING GLAD METAL ARTICLES.

APPLICATION FILLED JUNE 13,1908.

Patented July 6, 1909.

, 3% i m Q Inventor:

v Attyd M. M T. m 4

UNITED STATES PATENT OFFICE. JOHN nnoimor, on NEW YORK, N. Y., ASSIGNORDUPLEX METALS GOMPANYQOF New YORK, N. Y., A CORPORATION OF NEW YORK.

rnlocnss'or name emu-urn. an'rrcnns.

Specification of Letten Patent.

Patented Jul 6, 1909.

Application filed June 18, 1908. Serial No. 438,896.

face of themetal which is to form the cover- 7 To all whom it mayconcern:

Be it known that I, JOHN F. Mormo'r, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented a certain new and useful Process of Making Clad-MetalArticles; and'I do hereby declare the following to be a full, clear, andexact descri tion of the same, suchas will enable others s illed in theart to which it appertains to make and use the same.

My invention relates to a process of making clad metals; by which termis meant bodies comprising a core or base of one metal (iron or steelfor instance) having united thereto, and preferably inseparably unitedor-welded thereto, a substantial layer or coating of metal, usually anunlike metal, (for instance, copper, silver, gold, aluminum, brass,bronze, aluminum bronze, etc).

' particular, my invention comprises a process of making clad metalingots; which ingots,

when formed, may be rolled, pressed, hammered, or otherwise extendeddown to rods, sheets,"bars, strips, wire and other commerf cialordesired forms.

In various prior patents and applications for patents, :for example,Patents Nos.

851,993, 853,716, and applications Sr. Nos, 281,680, 391,673, and400,843, I haveillus-'- trated and described processes and apps ratusfor producing cla metal bodies or ingots such as referred to,andcomprising various pairs of unlike metals such as referred toinseparably weldeddogether, such' pro c--, based on a discoverysmade byme, Q

, pper and silver for exam 'le, which donot form-a peresses being A tothe eii'ect that various meta manent aor wel -like union with iron or'steel when cast against aniron orsteel surface at ordinary castipitemperatures, do form {get- ;1 raised a" :manent weld e unions when muchhigher temperature (termed by me, for the sake of a name, thesupermolten temperature) and contacted with the iron or stee surface.The said patents and applicationsdisclosemethods of and ,means forcontaotinga solid base of one metal, steel for .examplefwith moltenmetal of an unlike nature, copper for example, under such conditions .oftem erature and physical contact that union wil take place.

A processinvolvin the casting of the core or base, metal, whi 1 isusualb relatively large in amount inside of or against the sun-1;

, forth in ing or coating of the in ot or other article to be producedand whlch is usually relatively small in amount-for example, a processinvolving the castin of a steel core -or base inside of a copper sell-has numerous advantages from a practical pointof view. In such aprocess, ingots ofany desired size may be produced; the apparatusrequired is pro ortionately less expensive and more covering .of thesurface with the molten oxidation :of the metal and of preventin Isurface of the cast meta as well as other difiiculties which might bementioned, have militated against the use of any such process, however.To produce, a metallic union between two metals it is-necessary thatsuch 111161 1318 shall come into contact with clean,

trul metallic surfaces, free of infusible 01ml; or impurities, along theline of intended union.- It has been difiicult, furthermore, to preventthe cast -steel core from pullin away from the solid coatlng, durlng theso 'dification and shrinkin of the cast core. And in 'unitinga molten'gh-mjeltmg core metal with ,a sohdloWer-mel-tmg coating metal, therehas been extreme probability that the'coa-ting metal will becontaminated to a considerab e extent by the core or ,base metal, owingtopartlal iuslon of ,the coating -metal'and consequent mingling of ,thetwo metals; Such contamination is exceedingly objectionable in,manywcases'; for examp e, in the making of metal for electrical.conductors.

The :method of casting metal ingots set my application Sr. No. 391,674,1nvolvm the passing of .the molten metal throu a layer of molten :Wl ingmatena, such use suitable flux, an the retarded cooling ofn large bodyof molten metal at oxidation e y handled, little manipulation isnecesthe top of the ingot, so that this body will remain fluid after themain portion of the ingot has set and will flow down to fill any pipesor the like which may form, and Will also exert a certain amount offluid pressure to solidify the metal, overcomes these difficulties, andmakes it possible to cast a steel core inside of a copper shell, and toobtain a dense, solid core; and the same layer of wiping materialthrough which the metal for this core is cast, also serves to remove anylayer of oxid or other contamination on the surface of the said shell,besides preventing contact of the air with the portion of the solidmetal immediately above the molten metal andv necessarily heated to ahigh temperature. This layer of wiping material further removesentrained and occluded gases, oxid impurities, etc. from themoltenmetal, preventing the formation of bubbles, blow-holes or blebswhere the cast metal core contactswith the said coating metal andallowing a full-area contact between truly metallic surfaces of the twometals. It is extremely important, in the making of clad metal articlesintended to be extended or worked, to avoid any such flaws at thesurface of union, as any such flaws, if formed, extend greatly duringthe subsequent working and extension of the clad metal, producing whatmay prove to be serious defects in the final product. For example, inthe case of clad metal ship plates, consisting of a steel base or backand a co per, brass, bronze, Tobin bronze, or li e coating, a bubble orblow-hole at the line of union in the large ingot, may in the finalplate form a lineal flaw or pore which will admit sea-water to the steelback, permitting galvanic action between the metals of the back and ofthe coating, which will result in the weakening and finally in theperforation of the plate. asting the molten steel through wipingmaterial, as described, avoids the presence of the gas to which suchbubbles or blow-holes are due, ermitting the two metals to come intoabso ute metallic contact at all meeting oints. This method of castingthrough mo ten wiping material also makes possible the casting of themetal of the said shell or coating itself, immediately in advance of thecasting of the metal of the core or base. Heretofore this has not beenpracticable, because cast copper or like metal usually contains numerousinternal flaws, blow-holes, etc. which make it necessary to roll -orotherwise work it before it can be used as such a-coating or shell. Butmetal east through wiping material is practically free from suchinternal flaws. 1

The preferred method of carrying out my present process, therefore,supposing the article to be produced to be an ingot composed of a steelcore and a copper or other non-ferrous coating, comprises casting themetal for this coating in a suitable mold containing acollapsibleorotherwisc removable core adapted to form inside the coatinga space sullicient for the cast core, such casting being done through alayer of molten wiping material; in removing the said collapsible coreas soon as the metal for said coating has set, and in then casting intothe space from which such core was removed, the molten steel to form thecore of the ingot, such casting being also done through a layer ofmolten wiping material. And preferably, to cause rapid shrinking of thecoating, so that there can be no separation of the cast core from it, Ichill the mold as soon as, or soon after, the core has been cast. Thischilling is further advantageous in many cases, because copper and manyother metals are softer, closergraincd, and altogether better if cooledquickly from the molten state. This chilling also obviates fusion of thecoating metal and consequent mingling of the two metals, with consequentimpairment of quality of the metal of the coating.

In the accompanying drawing I illustrate apparatus for carrying out mysaid process, and the manner of carrying it out.

Figure 1 shows a central vertical section of one form of mold which maybe used, and with one form of collapsible core which may be used inplace in said mold; also a layer of molten metal for the coatin in theannular space between the core and sides of the mold, and a layer ofmolten wi ing material above such molten metal. .ig. 2 shows a similarsection (except that the section is not taken through the two "runners,as is the section of Fig. 1) of the mold after the shell for the coatinghas been cast and solidified, and after the collapsible core has beenremoved and the runner for pouring the metal for the ingot core has beenput in lace. Fig. 3 shows a horizontal section of t e mold andcollapsible core, on the line aca: of Fig. 1..

In the drawings, 1 designates an ingot mold, which in most cases may beof iron;

and 2 designates a collapsible core of the size v required to give thedesired size of cast core in the final ingot.

3, 3, designate inclined runners on opposite sides of the mold, throughwhich molten metal for the coating may be poured into the mold from twosides at once. v

4 designates a cooling jacket with which the mold may be provided, andwhich is provided with means for introducing into it or four side-pieces7. The mo d l has at its 'dra t in the mold.

a suitab mixture or wash, to prevent the molten metal bottom a shallowrecess 8 in which the lower end of the core may be stepfpgigsaidlrfipess o to 0 its serving to center the core an sections togetherat the bottom; and at its upper end the core has a clamp 9 which servesto hold its sections together.

10, Fig. 2, designates a runner of refractory material which is appliedto the mold after the shell for the coating has been cast and when themetal for the ingot core is to be cast.

The mold 1 is preferably formed of a lurality of sections securedtogether, w 'ch pur ose I have shown clamping rings 11 and We ges 12.The mold shown is made in two sections, so that it will part to permitre.

moval of the cast ingot. A mold made in a meter number of sections willserve as we 1, or even better. It is desirable to avoid employing a moldwith material draft, so that the coating may be of substantiallythe samethickness, and the cast core of substantially the same diameter, at theto as at the bottom; and employing a mold w 'ch parts lon 'tudinallymake t possible to avoid The method of carryin been clam ed together, asshown in Figs. 1 and 2, and the collapsible core 2 being in lace asindicated in Figs. 1 and 3, and the inside of the mold and the surfaceofthe core 2 havin preferably been given a coatinglof dc substance, forexample a grap 'te clingin to them, molten metal, copper for examp e,ispoured into the annular space between the core 2 and the sides of themold through a layer 13 of molten wiping material previously introduced,the metal being preferably introduced from a pluralit of pointssimultaneously so that it will iii the mold quickly. In descending throuh of wi ing'material, which should be of substantlal thicluiess, themolten metal is freed of adhering, absorbed and entrained .moisture andgases so that theseveral drops or bodies of'sucli metal meet beneath theayer with clean, readily coalescmg surfaces form ing a sound and perfectcasting. And as the;

molten wiping material rises above theaccu mulating molten metal, itsimilarly wip th surfaces of mold and core, permitting the, Cast-1 ingto take an accurate shape and have a good surface, free of blebs,pitholes, etc. The molten copper is poured 1n until it; about reachesthe top of the jacket 4, andthen the pouring is stopped,-and the moltenmetal is.

permitted to solidify. To hasten solidifica tion, cooling water or othercoolingfluldmay be introduced into or circulated through the jacket 4,though in general cooling will not out the process is. as follows: Theparts 0 the mold havingthe layer be necessary at this point. As soon asthe molten metal, which now forms a shell 14, has set and while it isstill redhot or hotter, the'collapsible core 2 is removed, the layer ofwiping material now flowing down to the bottom of the central space 15from which the core'2 was removed, the runner 10 is put wiping material,which rises as the steel fills the central space 15. Steel is so pouredin molten wiping material then forming over the top of the molten metala protective covering of relatively low heat conductivity; and since therunner 10 is also of a material of metalin the runner is relativelyslow. As soon as the mold has been filled as described water or'othersuitable cooling fluid is admitted to or circulated through a coolingjacket 4, so preventin the copper shell from melting and chilling tocontract with the cast steel inside it. As the copper shell coolsit willin turn cool the adjacent portion of the cast steel core, causing themetal below the runner to cool more rapidly than the-metal within therunner, the lattermetal remaining liquid until the metal below hasfullyset. Any pipes or the like which may form during the solidification of the cast core are filled by dow'nflow of metal from the runner;and the fluid ressure exerted by the metal in this runnera ohelps toinsure good density of the cast metal. Preferably the ingot so cast isremoved from diately worked, by rolling or otherwise; or it may besubjected to pressure while still fluid ods of pressure-casting.

W1 oxi and like impurities, entrained and oc-' cluded gases, and insuresa particularly good in the mold is at alltimes covered by anairexcludinglayer ofwiping material. .difierent wipinginateria s may beused; one

.solid t e mold, if desired.

wouldbe an obvious modificatign of the process above describedto castthe steel core within mold 1, remove the said sectional mold when thesteel core is solid, andthen cast molten coating metal, through wipingthe shell and causing it the mold as soon as practicableandis immein themold, according to well-known moth-V The casting of both metals throughmolten I V ing material as described removes all Var ous in place, andmolten steel for the core'is poured into this central space, through theuntil space 15 is full and the runner 10 is also partly filled with themolten metal, the

low heat conductivity, cooling of the molten quality of metal, if theprocess .is carried on properly. Oxidation of the metal during the"casting, is precluded, since the molten metal. 11s

suitable material being a mixture d sodium 'orgotassium silicate, bore]:and boracic acid. v f' course my process'described aboveisj not to theproduction ofthe 811811111; bycasting as described the shell 14 may Vproduced in an suitable manner, and ladced n it 1 first, within asectional mold contained the ingot as described.

1 holes and the like.

material, into the space between said core and the sides of mold 1;afterward working It may be that the steel, when it first contacts withthe solid cop er, produces actual or incipient fusion of t 1e copper onthe extreme surface; such fusion, if it occurs, facilitating theformation of a union between the two metals. But the cooling of thecopper shell as described prevents any materia fusion such as willresult in material contamination of the copper by the metal of the core.

If desired or required, after theremoval of the collapsible core fromthe mold, after casting the annular body 14, additional flux or wipingmaterial may be poured into the interior of such annular body tocompletely fill it, so absolutely protecting its surfaces from oxidationandremovin any trace of oxid which may have been already formed, so thatan absolutely clean surface of the metal is exposed when the moltensteel displaces this flux or wiping material.

I do not limit the rocess to top pouring, but'may pour throug the bottomof the ingot mold, as is common in steel practice, if desired.

It is obvious that the same process above described is equally aplicable to the formation of objects in wine 1 neither metal completelysurrounds the other; for example, ob]ects in whichone body of metalabuts against, without surrounding, the other; in such case the moldused will have a removable filling piece, corres onding to thecollapsible core 2, which will fill that portion of the mold which is tobe occupied by the body of metal cast last; and the body of metal firstcast will be cast into the remaining ortion of the mold, and after ithas solidi ed the said filling piece will be removed and the other bodyof molten metal cast.

Instead of first casting a cop er or like metal body, permitting it toso idify, and then casting molten steel against the surface of thesolidified copper or other metal,,I may cast the steel and thenon-ferrous metal practically simultaneously, by lacing a suitableseparator in the mold and casting the one metal on one side of the searator and the other metal on the other side of the separator; castingboth metals through molten wiping material, as already described, so asto obtain dense, sound metal free from blow- Thus, in the making of acopper-steel round ingot, I may lace a steel tu e of suitable size inthe mo (1, and cast copper, through flux, either inside or outside thetube, according as the copper is desired either on the inside or outsideof the finished product, casting the steel on the opposite side of thetube, casting through flux or wiping material in both cases. And inmaking fiat or square ingots the same method may be employed, a suitableseparator being placed in the mold to keep the two metals separateduring the pouring. In casting by this method, both metals will weld tothe separator, and so will in effect be welded to the ingot may berolled, without reheating,

immediately after the steel has solidified and while it is still at amuch higher temperature than the copper or other coating metal. Rollingclad metal ingots produced by casting the copper or the like about thesteel, presents certain practical disadvantages, owing to the fact thatthe ingot must be rolled at a temperature at which the copper or likemetal issolid, which is not necessarily the best working temperature forthe particular steel em loyed; and after the ingot is once produce itcan be heated only from the outside, that is to say, through the copperor like metal, so that on such reheating its interior temperature cannotbe higher, initially, than its exterior temperature. But when the ingot,produced as described herein, is rolled without reheating, the steel maybe at a much higher temperature than the copper, first because itsolidifies at a higher temperature, the copper being kept at a lowertemperature in the mold bythe cooling means described, and then when theingot is removed from the mold and rolled, radiation of heat to the airand the higher heat conductivity of the copper will keep the temperatureof such copper materially lower than that of the steel inside. For thisreason the ingot so produced is much easier to work by rolling orotherwise, and no reheating before rolling is required.

What I claim is 1. A process of making clad metal objects whichcomprises forming a compound ingot by casting molten metal of relativelyhigh melting point through a layer of molten wiping materialin an ingotmold and against the surface of a solid body of metal of lower meltingpoint and causing it to solidify thereagainst.

2. A process of making clad metal objects which comprises casting moltenmetal of relatively high'melting point through a layer of molten wipingmaterial against the surface ofa solid body of metal of lower meltingpoint andcausinglit to solidify thereagainst,

and abstracting eat from the solid metal during contact with such moltenmetal.

3. A process of making clad metal objects which comprises forming acompound in ct by casting molten metal of'relatively high melting pointthrou h a la er of molten wiping material into t e interior of anannular body of metal of lower melting point, and causing'it to solidifyagainst the surface of such annular'body.

4. A process of making clad metal objects which com rises casting moltenmetal of ing material into contact with a solid bo y I ferrous metalhr'ough rial into the interior of an annular of metal consisting inwhole or in greater part of non-ferrous metal, and permitting the moltenmetal to solidify against such body. 6. Aprocess of forming clad metalobjects which consists in casting a molten body of a layer .of moltenwiping material 'into contact with a solid body of er and permittingthemolten meta to co 'soii ify against suchhody. 7 A process ofform'ingclad metal objects which consists in casting a molten body-50f ferrousmetal through a layer of molten wiping material into contact with asolid body of metal consisting in whole or in greater part ofnon-ferrous metal, and permitting the molten metal to solidify againstsuch surface and abstracting heat from such solid metal during contactthereof with the molten metal.

8. A process of forming clad metal objects which consists in castingamolten bed of ferrous metal through a layer of mo tan with a solidwiping material into contact V p the molten body of'co er and permitt'metal to so idify againstj'suchody and abstracting heat contact 'thereofwith the molten metal.

9. A process of forming-clad metal objects which consists in castingmolten ferrous" ing material metal through a layer of'wi ody of metalinto the interior of an annular consisting 'in whole or greater part ofnonmolten face of the body ferrous metal andpermitting such metal tosolidify ainst such body. 7 10. A process 9 forming clad metalobs jectswhich conslsts'in casting molten ferrous metal through a layer of wipingmateco er and 'ermitt' such molten metal to SOEE P ft ify against sucody.

11. A process of forming clad metal objects which consists in castingmolten ferrous metal through a layer of wi in material into the interiorof an annular bofy of metal consisting in whole or greater part ofnonferrous metal and permitting such molten metal to solidify againstsuch body, and

jects which consists from such solid metal during ody of abstractingheat from such annular body during contact thereof with the moltenmetal.

12. A process of forming clad metal ob: jects which consists in castingmolten ferrous metal through a layer of wipin mate rial into theinterior of an annular ody of copper and permittin to solidifv againstsuc body, and abstracting heat from such annular body during contactthereof with the molten metal.

13. A process of forming clad metal obin contacting with the surface ofa solid body of metal a layer of molten flux comprising oxid-dissolvingmaterial, casting through such layer of flux into contact with thesurface of such metal, a body of molten metal of higher melting pointand by the progressive rise of the layer of flux removing oxid'from thesurface of the solid metal and exposing a clean surface of such metal tocontact with the molten metal, and permitting the molten metal tosolidify against such surface. v

14. A process of forming cladmetal objects which consists in contactingwith the surface of a solid body of metal a layer of molten fluxcomprising oxid-dissolving material, casting into contact with suchsurface. a body] of molten metaland causing the molten metal so cast toraise the layer of flux and thereby to ex ose progressively a cleansurface of the so id metal to contact with the. molten metal,- andpermitting the molten metal to solidify against such surface.

15. A process of forming clad metal objects which consists in contactingwith the inner surface of an annular body of metal a layer of moltenflux comprising oxid-dissolv ing material, casting into the space withinsaid annular body a body of molten metal andcausing the molten metalsocast to raise the-layer of flux and thereby to expose progressively aclean surface of the so 'd metal to contact with the molten metal, andpermitting the molten metal to solidify against such surface.

such molten metal 16. A process of forming clad metal objects whichcomprises casting a bodv of mol ten; metal and permitting it tosolidify, producing a substantial layer of flux next a sur so formed andwhile sa d :body is hot casting into contact with its said surfacethrough said layer another body of molten metal and causing such metalto displace saidilux, and ermitting such second ody of molten meta tosolidify against such surface.

17. A recess of forming clad metal obpermitting it to solidify,

jects whlch com rises casting a body of molten metal an producing asubstantial layer of flux next a] surface of the body so formed andwhile said body is hot casting into contact with its said' surfacethrough said layer another body of molten metal and causing such metalto dis place said flux, permitting such second body of molten metal tosolidify against such surface, and abstracting heat from such first bodyof metal during contact thereof with said second body of molten metal.

18. A process of forming clad metal objects which comprises casting abody of molten metal through a layer of wiping material, and permittingthe metal to solidify, and While said body is hoteasting into contactwith a surface of it, through a layer of wiping material, another bodyof molten metal, and permitting such second body of molten metal tosolidify against such surface.

19. A process of forming clad metal obj ects which comprises casting abody of molten metal through a layer of wiping material, and permittingthe metal to solidify, and while said body is hot casting into contactwith a surface of it, through a layer of wiping material, another bodyof molten metal, permitting such second body of molten metal to solidifyagainst such surface, and abstracting heat from such first body ofmetal, during contact thereof with said second body of molten metal.

20. A process of forming clad metal 0bj cots which comprises casting abody of molten metal through a layer of wiping material, and permittingthe metal to solidify, protecting a surface of such body from oxidationWith molten flux and while said body is hot casting into contact withsuch surface,

through flux, another body of molten metal, and permitting such secondbody of molten meta to solidify against such surface.

21. A process of formingclad-metal objects which comprises casting abody of molten metal and permitting the metal so cast to solidify whileprotecting such metal against oxidation, casting into contact with thesurface of the body so produced another body of molten metal underconditions precluding oxidation and permitting it to solidify againstthe surface of said first body, and abstracting heat from said firstbodyof metal at such rate as to permit refusion of only a thin layer thereofadjacent the second body of metal, thereby insuring molecular contact ofthe two metals and avoiding material mixing thereof.

22. A process of working, by rolling, pressing, hammering or the like,clad metal bodies, which consists in maintaining the core, of metal ofhigher melting point, at a temperature higher than that of the coating,of metal of lower melting point, and working same by rolling, pressing,hammeringor the like while maintaining a temperature differ-- entialbetween the two metals.

23. A process of forming compound metal objects which comprises placinga separator in a suitable mold and casting different kinds or grades ofmetal, through molten wiping material, on opposite sides of saidseparator,

causing the two metals in solidifying to weld to the separator and so toeach other.

In testimony whereof I afiix my signature, in the presence of twowitnesses.

JOll N 3 MO NOT. Witnesses:

H. M. MARBLE, K. G. LE ARI).

